Background: Bullying is a social problem characterized by intentional aggression
over time, usually in school contexts and in cyberspace, characterized by intentionality, repetition, and power asymmetry. Bullying victimization during school years is a serious global health problem with those students experiencing bullying having an increased risk of physical, cognitive, and mental health issues. Aim: This study aimed to assess bullying among preparatory school students. Research design: descriptive research design was used in this study. Sample: Simple random sample includes 150 students. Setting: Hudaa Sharawy, El-kholafaa El- Rashedeen and El-Shaheed Ahmed Hamdy preparatory schools. Tool for data collection: one tool includes four parts, 1st part include socio-demographic characteristic, 2nd part assess students' knowledge about bullying, 3rd part assesses the effect of bullying on students' health status, 4th part assess students reported practice. Results: it revealed that 54 % of the studied sample had average knowledge while only10% of them had good knowledge. 44.7% of the studied sample had total satisfactory health practices Conclusion: more than half of the studied sample have average knowledge, more than one third of them have satisfactory practice about bullying and there are non-significant association between total knowledge and total practice when P=0.07. Recommendations: Provide prevention program and orientation sessions about bullying for school students